Keyboard



FIG. 1 is a front-right-top perspective view thereof;

FIG. 2 is back-left-top perspective view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a left view thereof.

FIG. 6 is a right view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a view of the top face thereof.

The broken lines form no part of the claimed design. 

The ornamental design for a keyboard, as shown and described. 